• Journal of Korean Academy of Nursing
• /
• v.50 no.6
• /
• pp.757-777
• /
• 2020

Purpose: The purpose of this study was to identify the outcome variables of nursing unit managers' transformational leadership and to test a hypothetical model using meta-analytic path analysis. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. Data analysis, conducted using R version 3.6.2 software, included 49 studies for the meta-analysis and 119 studies for meta-analytic path analysis. Results: In the meta-analysis, four out of 32 outcome variables were selected. These four variables were empowerment, nursing performance, job satisfaction, and organizational commitment, which showed larger effect sizes than the median and more than five k. The hypothetical model for the meta-analytic path analysis was established by using these four variables and transformational leadership. A total of 22 hypothetical paths including nine direct effects and 13 indirect effects were set and tested. The meta-analytic path analysis showed that transformational leadership had direct effects on the four variables. Finally, eight direct effects, 12 indirect effects, and six mediating effects were statistically significant, and the hypothetical model was verified. Conclusion: Nursing unit managers can use the transformational leadership to improve empowerment, nursing performance, job satisfaction, and organizational commitment of nurses. This study empirically showed the importance of transformational leadership of nursing managers. This finding will be used as evidence to develop strategies for enhancing transformational leadership, empowerment, nursing performance, job satisfaction, and organizational commitment in nursing science and practice.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.4
• /
• pp.452-459
• /
• 1998

The purpose of this study was to discover a conceptual framework and evaluation process of apparel quality by means-end chain theory. The theoretical study was conducted to find out a conceptual framework and build a hypothetical evaluation process model of apparel quality. Apparel quality was perceived associative network called a means-end chain and was evaluated in several stages. A conceptual framework of apparel quality evaluation was organized into hierarchical relationships among four different dimensions: physical attribute, physical function, instrumental performance, and expressive performance. The means-end structure linked tangible physical attributes and function to more abstract instrumental and expressive performance. A hypothetical evaluation process model linked dimensions of apparel quality to the selected means-end relationship. Different consumers had different means-end chains for the same apparel. Therefore different subjects are likely to have different evaluation paths. From this study we can suggest an evaluation process model of apparel quality.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.39 no.2
• /
• pp.83-95
• /
• 2014

In this paper, we develop a portfolio selection model that can be used to invest in markets with margin requirements such as the foreign exchange market. An investment algorithm to implement the proposed portfolio selection model based on objective historical data is also presented. We further conduct empirical analysis on the performance of a hypothetical investment in the foreign exchange market, using the proposed portfolio selection model and investment algorithm. Using 7 currency pairs that recorded the highest trading volume in the foreign exchange market during the most recent 10 years, we compare the performance of 1) the Dollar Index, 2) a 1/N Portfolio which equally allocates capital to all N assets considered for investment, and 3) a hypothetical investment portfolio selected and managed according to the portfolio selection model and investment algorithm proposed in this paper. Performance is compared in terms of accumulated returns and Sharpe ratios for the 10-year period from January 2003 to December 2012. The results show that the hypothetical investment portfolio outperforms both benchmarks, with superior performance especially during the period following financial crisis. Overall, this paper suggests that a mathematical approach for selecting and managing an optimal investment portfolio based on objective data can achieve outstanding performance in the foreign exchange market.

• Journal of the Korea Society for Simulation
• /
• v.32 no.1
• /
• pp.13-21
• /
• 2023

This paper proposes a method of automatically generating a model through a machine learning technique by setting a hypothetical model in the form of a gray box or black box with unknown parameters, when the big data of the actual system is given. We implements the proposed framework and conducts experiments to find an appropriate model among various hypothesis models and compares the cost and fitness of them. As a result we find that the proposed framework works well with continuous systems that could be modeled with ordinary differential equation. This technique is expected to be used well for the purpose of automatically updating the consistency of the digital twin model or predicting the output for new inputs using recently generated big data.

• Nuclear Engineering and Technology
• /
• v.54 no.6
• /
• pp.2120-2134
• /
• 2022

A hypothetical core destructive accident (HCDA) has received widespread attention as one of the most serious accidents in sodium-cooled fast reactors. This study combined recent advantages in numerical methods to realize realistic modeling of the complex fluid-structure interactions during HCDAs in a full-scale sodium-cooled fast reactor. The multi-material arbitrary Lagrangian-Eulerian method is used to describe the fluid-structure interactions inside the container. Both the structural deformations and plug rises occurring during HCDAs are evaluated. Two levels of expansion energy are considered with two different reactor models. The simulation results show that the container remains intact during an accident with small deformations. The plug on the top of the container rises to an acceptable level after the sealing between the it and its support is destroyed. The methodology established in this study provides a reliable approach for evaluating the safety feature of a container design.

• Journal of Korean Academy of Nursing
• /
• v.30 no.2
• /
• pp.366-379
• /
• 2000

The purpose of this study was to identify causal relationships among variables of transtheoretical model for exercise in the elderly A predictivel model explaining the stage of change was constructed based on a transtheoretical model. Empirical data for testing the hypothetical model was collected from 198 old adults over 60 years old in a community setting in Seoul, Korea in April and May,1999. Data were analyzed by descriptive statistics and correlational analysis using pc-SAS program. The Linear Structural Modeling (LISREL) 8.0 program was used to find the best fit model which predicts causal relationship of variables. The fit of the hypothetical model to the data was X2=132.85. (df=22, p=.000). GFI=.88, NNFI=.35, NFI=.77, AGFI=.59 which was not favorable but the fit of modified model to the data was X2=46.90. (df=27, p=.01).GFI= .95, NNFI=.91, NFI=.92, AGFI=.87) which was more than moderate. The predictable variables of stage of change for exercise of the Korean elderly were helping relationship, self cognitive determination, conversion of negative condition in process of change and efficacy for exercise. These variables explained 68% of stage of change for exercise of the Korean elderly.

• Journal of Korean Academy of Nursing
• /
• v.52 no.4
• /
• pp.363-377
• /
• 2022

Purpose: This study aimed to test a hypothetical model of Korean nurses' patient safety management activities using meta-analytic path analysis. Methods: A systematic review, meta-analysis, and meta-analytic path analysis were conducted following the PRISMA and MOOSE guidelines. Seventy-four studies for the meta-analysis and 92 for the meta-analytic path analysis were included. The R software program (Version 3.6.3) was used for data analysis. Results: Four variables out of 49 relevant variables were selected in the meta-analysis. These four variables showed large effect sizes (ESr = .54) or median effect sizes (ESr = .33~.40) with the highest k (number of studies) in the individual, job, and organizational categories. The hypothetical model for the meta-analytic path analysis was established using these variables and patient safety management activities. Twelve hypothetical paths were set and tested. Finally, the perception of the importance of patient safety management and patient safety competency directly affected patient safety management activities. In addition, self-efficacy, the perception of the importance of patient safety management, patient safety competency, and patient safety culture, indirectly affected patient safety management activities. Conclusion: Self-efficacy, the perception of the importance of patient safety management, patient safety competency, and the organization's patient safety culture should be enhanced to improve nurses' patient safety management activities.

• Journal of Korean Academy of Nursing
• /
• v.34 no.2
• /
• pp.333-343
• /
• 2004

Purpose: This study was designed to construct a structural model for symptom management of life of the patients with chronic fatigue. The hypothetical model was developed based on the literature review and Self-regulating Model. Method: Data were collected by questionnaires from 252 patients with chronic fatigue in the 8 community from December 2002 to April 2003 in Seoul. Data analysis was done with SAS for descriptive statistics and PC-LISREL Program for Covariance structural analysis. Result: The fit of the hypothetical model to the data was moderate, thus it was modified by excluding 4 path and including free parameters and 3 path to it The modified model with path showed a good fitness to the empirical data($x^2$=318.11, p=0.0, GFI=.98, AGFI=.98, NNFI=.95, RMSR=.03, RMSEA=.05). The symptoms of stress, self-efficacy, and present fatigue level were found to have significant direct effect on symptom management of the patients with chronic fatigue. The ways of coping, perceived stress, and fatigue symptom were found to have indirect effects on symptom management of the patients with chronic fatigue. Conclusion: The derived model is considered appropriate in explaining and predicting symptom management of the patients with chronic fatigue. Therefore, it can effectively be used as a reference model for further studies and suggested direction in nursing practice.

• Korean Journal of Adult Nursing
• /
• v.19 no.4
• /
• pp.547-555
• /
• 2007

Purpose: The purpose of this study was to test a hypothetical model of health-related quality of life in patients with heart failure. The hypothetical model was derived from the Wilson and Cleary's model, the Rector's model, and published research findings. Methods: Data from 103 patients with heart failure were analyzed to determine the best multivariate health-related quality of life model given variables derived from the prior studies. The statistics programs SPSS 12.0 and LISREL 8.7 program were used for descriptive statistics and covariance structure analysis respectively. Results: The overall fitness of the path final model was good(GFI=.97, AGFI=.95, NNFI=1.06, NFI=.96, p=.96). Symptoms were directly affected by gender. HYHA Class was directly affected by only gender. Physical functioning limitation was directly affected by exercise. Health perception was directly affected by economics, symptom, and physical functioning limitation. Depression was directly affected by exercise and health perception. Heath-related quality of life was directly affected by physical functioning limitation and depression, indirectly affected by gender, economics, exercise, symptoms, NYHA Class, and health perception. This path analysis model explained 51% of health-related quality of life in patients with heart failure. Conclusion: To improve of health-related quality of life with heart failure patients, it is necessary to make nursing interventions for physical functioning and depression.

• Journal of The Korean Association For Science Education
• /
• v.33 no.5
• /
• pp.981-994
• /
• 2013

This study aims to examine two hypothetical models for the variables of students' environmental perspective. First hypothetical model is the mediating role of recognition and familiarity between aesthetic and negativistic perspectives. Second hypothetical model is the separate path from humanistic to dominionistic perspectives. One hundred four tenth grade students participated in this study. We used Pearson correlation, partial correlation, and path analysis to examine the fitness of hypothetical models. The findings showed that the mediating role of recognition and familiarity between aesthetic and negativistic perspectives were statistically accepted. To prevent students' bias for fancy or gross animals, the learning (for instance, recognition and familiarity) may play role in reducing the bias. Second, there were two differential paths from humanistic to dominionistic perspectives (ecologistic-naturalistic path and scientistic-utilitarian path). While ecologistic-naturalistic path does not reach dominionistic perspective, scientistic-utilitarian path does reach dominionistic perspective. To prevent students' dominionistic perspective for nature, they need to understand ecologistic-naturalistic minds for the nature.